Following announcements by major retailers Tesco and the Cooperative late last week, Marks and Spencer and Sainsbury's withdrew their commitment to sourcing eggs and poultry meat from birds fed on a diet free from genetically modified material over the weekend.

Both supermarkets claim that sourcing GM-free feed has become a problem for their suppliers. Waitrose now stands alone as the only UK supermarket which has maintained its GM-free stance.

In its announcement, Marks and Spencer said its commitment to selling "non-GM food ingredients" remained unchanged. Sainsbury's said meat and eggs in its 'Taste the Difference' and organic ranges would still be GM-free.   

In line with EU guidelines, meat and eggs from poultry fed on a diet including GM grain will not be labelled in supermarkets, despite the results of a Food Standards Agency study which revealed almost 70 percent of the British public would like labelling laws extended to include this use of GM material. However, in line with citizens' desires, in many EU states animal products from animals fed on GM diets are labelled as such.

GM-sceptic groups in the UK have challenged the supermarkets' assertions that there is a difficulty in accessing GM-free feed. The organisations point to a massive lobbying push by poultry industry groups, including the British Poultry Council, British Egg Industry Council and NFU inciting UK supermarkets to drop their ethical sourcing policies on feed.

Commenting on the wholesale abandonment of GM-free policies by the UK's major retailers, Soil Association policy director Peter Melchett said, "M&S, Co-Op and Tesco are misleading their customers by claiming that non-GM feed isn't available. They are wrong. In Brazil alone, there is enough non-GM animal feed to supply the whole of Europe. The quantity of non-GM imported feed into Europe is going up year on year, because supermarkets in countries like France and Germany are avoiding GM feed."

According to a poll conducted by food industry magazine The Grocer on Friday, faith in supermarkets' integrity appears to be at an all-time low in the UK. The poll showed that 80 percent of Britons are either undecided on or opposed to GM foods and feed, but that less than 4 percent of those questioned believed supermarkets were being clear on the issue.

Peter Melchett added last week, "Tesco and the Co-Op are also misleading their customers by claiming that the GM feed will not be detectable in products like eggs, milk or chicken. This is not true. Several research studies have found that GM DNA in animal feed is taken up by the animal’s organs and can then be detected in the milk, meat and fish that people eat. This has been confirmed today by the Government’s Food Standards Agency."